August 7th, 2016

30 BRX Wildcat — a 30 BR Improved That Runs Significantly Faster

30 BR 6mmBR 30 BRX wildcat Al Nyhus

We first ran this story a few years back. But it’s still a very interesting subject for benchrest shooters. Shown above, the 30 BR (a 6mmBR necked up to .30 Caliber) currently rules the benchrest-for-score game. However, a 30 BR Improved offers some potential advantages, particularly when the winds are strong or tricky. In this article Al Nyhus explains his 30 BRX wildcat. Running Hodgdon H4198, Al says he gets an easy 150 -200 FPS more than the conventional 30 BR. That can translate to less drift in the wind. It also lets you pursue a higher speed node, which can lead to improved accuracy with some barrels.

30 BRX wildcat cartridge VFSForum member Al Nyhus is a top-level score shooter who has competed successfully with the 30 BR cartridge in VFS (Varmint for Score) matches. Al has been working on an “improved” 30 BR cartridge that delivers extra velocity. Al’s 30 BRX cartridge is inspired by the 6mm BRX cartridge, popular in 600-yard benchrest and across-the-course competition. The 6mm BRX cartridge maintains the same sidewall profile and shoulder angle as the parent 6mmBR case. Likewise, the 30 BRX retains the 30° shoulder used on the popular 30 BR cartridge.

Al reports: “Thought you might like to see what I’ll be working with in my VFS gun this season. It’s a true 30 BRX — a 30 BR with the shoulder moved forward 0.100″ with the standard BR shoulder angle. Stan Ware of SGR Custom Rifles built one last season for Steve Grosvenor and I was really impressed by the performance of Steve’s gun. The 30 BR barrel on my VFS gun needed replacing, so the new 30 BRX got the nod.”

30 BRX Delivers 150-200 FPS More Velocity than 30 BR
Al says his 30 BRX gives a solid 150-200 fps speed gain over the 30 BR at the top, while needing just 2.5-3.0 more grains of Hodgdon H4198 to do so. A 30 BR case holds on average 40.8 grains of water, while the 30 BRX holds 42.3 grains (roughly 4% more). So the 30 BRX delivers a 7% increase in velocity with a mere 4% increase in H20 capacity. That’s pretty good efficiency. [Editor’s Note: Assuming 34 grains of H4198 is a typical 30 BR match load, Al’s increase of 2.5-3.0 grains for the 30 BRX represents roughly a 7.5-8.5% increase in actual powder burned. That explains the higher velocities.]

Why did Nyhus decide to try an “improved” 30 BR?

Al explains: “The 30 BRX was created to operate at a [higher] velocity level than can be achieved with the standard 30 BR case, while at the same time keeping the easy-tuning characteristics of the standard 30 BR case. We also wanted to use the same powders currently used with the 30 BR and maintain similar operating pressures.” Is the 30BRX harder to shoot because of the increased velocity? Al doesn’t think so: “In a 13.5-lb HV gun, the 30 BRX case is a pleasure to shoot with just a flea bite of recoil.”

Will the 30 BRX Replace the 30 BR in Score Competition?
The 30 BR is already an exceptionally accurate cartridge that dominates short-range Benchrest for Score competition. Will the 30 BRX make the standard 30 BR obsolete? Nyhus doesn’t think so. However, Al believes the 30 BRX offers a small but important edge in some situations: “On any given day, it’s the shooter that hits the flags best and makes the fewest mistakes that ends up on top. No amount of velocity will save you when you press the trigger at the wrong time. Missing a switch or angle change at 200 yards that results in 3/4″ of bullet displacement on the target can’t be compensated for with another 200 fps. That’s the hard fact of benchrest shooting. But on those days when, as Randy Robinett says, ‘our brains are working’, the BRX may offer enough of an advantage to turn a close-but-no-cigar 10 into an ‘X’ at 200 yards. Or turn a just-over-the-line 9 into a beggar 10.” Given the fierce competition in Score matches, an extra 10 or another X can make the difference between a podium finish and also-ran status.

Permalink Bullets, Brass, Ammo, Competition No Comments »
August 7th, 2016

Prescription Eyewear for Older Shooters

vision RX Prescription glasses for shooters

Shooting Sports USA has published an informative article covering prescription eyewear for shooters. In The Right Rx for Aging Eyes, writer Chris Christian reviews vision issues with Doctor of Optometry Alexis Rodriguez. Christian notes that many shooters have difficulty focusing on their sights as their eyes age. Even if you use scopes more of the time, we recommend you read this article, which explains the physiology (and bio-mechanics) of human vision.

Shooters experience vision issues as they get older, explained Dr. Rodriguez: “Presbyopia is the medical term that describes the natural deterioration of the eyes with age.” As people get older, the ability of the eyes to focus on near objects is diminished, due to the loss of elasticity of the crystalline lens inside the eye and the gradual deterioration of the ciliary muscles that help in bending the lens to focus. Rodriguez says the first symptoms usually occur around age 40, although some will experience them later. This normally starts with blurriness when looking at close objects. From that first point, this natural deterioration will continue to worsen until around the age of 65, where it normally stabilizes, and virtually all elasticity of focus is gone.

To overcome focus problems associated with aging eyes, Dr. Rodriguez often recommends a modified bifocal design for shooters. The lower insert is set to the shooter’s Sight Distance (SD) instead of a standard “reading” distance and the insert lens is moved upwards in the lens to a point in line with the bottom of the pupil. This allows the shooter to maintain a constant head position to access the lower lens and reduces image jump.

READ Full Article on Vision Correction for Shooters at SSUSA.org

Permalink - Articles, Optics 2 Comments »
August 7th, 2016

Recommended Resource: Ammo Encyclopedia (5th Edition)

Brussard ammunition encyclopedia 5th Edition

Wouldn’t it be nice to have a print resource at your fingertips that has hundreds of true-size cartridge illustrations, plus technical descriptions of thousands of popular cartridge types? That could be a real time-saver. It’s no wonder this book is an Amazon best-seller in its category.

If you’re a serious shooter, the latest 5th Edition of the Ammo Encyclopedia belongs in your library. This 1008-page book by Michael Bussard is probably the most comprehensive and up-to-date book in print covering current and obsolete cartridges and shotshells. The Ammo Encyclopedia is a massive resource work. The 5th Edition now boasts 105 chapters, covering thousands of handgun, rifle, and shotgun cartridges from the past century and a half.

One of the best features is a 12-page color section depicting actual size drawings of 265 current rimfire/centerfire cartridges and shotshells. You won’t find that many “life-size” cartridge drawings in one place even on the internet. Cartridge profiles and ballistic charts have been expanded to include all new factory cartridges. The authors have even included air rifle pellets and historical images and charts. Softcover, 1008 pages — edited by S.P. Fjestad.

Brussard ammunition encyclopedia 5th Edition

Comments from guys who bought the book:

“This book contains a vast array of information on many modern and even obsolete ammunition. Definitely recommend for any modern reloader novice or experienced.” – Duggaboy460

“It’s a great reference book for individuals who reload their own ammunition. There is a lot more info in this Edition. Everyone who likes this information should have it in their library.” – Reloader

“I like the general and technical comments that are available for each and every cartridge. Information that predicts if a cartridge will stay in production for many more years or rapidly become obsolete.” – RSL1

Permalink Bullets, Brass, Ammo, Reloading 2 Comments »